(19)

(11)

EP 0 061 490 A1

(12)

(43) Date of publication: 06.10.1982 Bulletin 1982/40 (21) Application number: 81902848.0 (22) Date of filing: 30.09.1981

(51) International Patent Classification (IPC):  E21B 19/ 20( . ) E21B 19/ 15( . ) (86) International application number: PCT/US1981/001322 (87) International publication number: WO 1982/001212 (15.04.1982 Gazette 1982/10)

(84) Designated Contracting States: FR (30) Priority: 30.09.1980 US 19800192477 30.09.1980 US 19800192495 (71) Applicant: INGRAM CORPORATION New Orleans, LA 70139 (US)	(72) Inventors: FRIAS, Robert Odessa, TX 79761 (US) MINNIS, C.W. Fort Worth, TX 76117 (US) HAWKINS, Hubert A. Fort Worth, TX 76101 (US) DAVIS, Wendell Fort Worth, TX 76101 (US) (74) Representative: Descourtieux, Philippe  Cabinet Beau de Loménie 158, rue de l'Université F-75340 Paris Cédex 07 F-75340 Paris Cédex 07 (FR)